Published online by Cambridge University Press: 21 February 2011
An in-depth review of controlled collapse chip connections (c-4), or otherwise known as Flip Chip Solder Joining Technology, is present. The C4 joint utilizes solder bumps deposited on wettable terminals on the chip and a matching footprint of the substrate. The upsidedown chip (flip chip) is aligned to the substrate and all joints are made simultaneously by reflowing the solder. An in depth review of this technology is presented. Materials, design factors, fabrication processes, tools, assembly, rework, and reliability are discussed. Future trends are indicated and comparisons make with wire bonding and Tab (tape automated bonding).